The research has as its objective the solution of two related problems: (1) the nature of the biochemical events involved in the synthesis of protein by animal cells (especially the structure and function of ribosomes); and (2) the mechanism whereby insulin (and perhaps other hormones) participate in the regulation of protein synthesis-- it follows, as a corollary, that we wish to gain an understanding of the character of the defect in protein metabolism that occurs in diabetic animals. We propose then to examine the effect of diabetes and insulin on individual steps in protein biosynthesis, especially on the process of translation and its initiation. We plan during the coming year to carry out the following studies: (1) The isolation, purification and characterization of initiation factors from ascites cells. (2) We shall use the initiation factors to carry out a comparison of the ability of normal (N) and diabetic (D) ribosomes to translate encephalomyocarditis virus (EMCV) RNA with the intention of further characterizing the difference. (3) A comparison of the ability of N and D ribosomal subunits to reassociate (and form 80S monomers) in the reaction catalyzed by the eukaryotic initiation factor EIF-1. (4) A comparison of the ability of N and D 80S ribosomes to serve as a substrate for the dissociating activity of EIF-3. (5) Devise the means and carry out assays in N and D muscle of the elongation factors (EF-1 and EF-2) and of initiation factors (EIF-1, EIF-2, EIF-3). We have devised assay for those factors. (6) We hope to complete studies on the nature of the effect of adrenalectomy on protein synthesis in muscle. (Adrenalectomy causes an apparent doubling of the synthesis of protein in isolated rat diaphragm muscle.)